How to impose a record type on the creative from the child object.

Hello,

I am currently working on a model for a French energy supplier. I encounter a simple problem for which I do not know of any solution.

Here is the situation:

I have 2 types of accounts, Installation and Company.
I must be able to create a "case" that references for a 1st field a company of type installation and for 2nd an installation.

So I have 2 "case" relationships to account, a standard and a custom to which I apply search filters.

The problem is that for account records that does not exist yet when creating the case. Users are prompted to create a record and a pop-up window asks to select the type of record to create.

I would like to override the request of the type to force the creation of one or the other according to the selected field for the creation.

Here are some pictures to understand my problem.
Case creation screen
User-added image